Method of retaining a first housing to a second housing using a self-tightening clip

Abstract

A self-tightening clip having a planar member and at least one retention member attached to the planar member. The planar member includes an inner perimeter, an outer perimeter, and defines a central axis. The least one retention member including a planar leg portion and a planar hook portion. The leg portion extends from the inner perimeter in a first direction along the central axis. The hook portion projects from the leg portion toward the central axis in a second direction, which is opposite the first direction along the central axis. The hook portion is acute to the central axis and has a free end located on an imaginary perimeter concentric to the inner perimeter of the planar member. The central axis and a plane passing through the hook portion of the at least one retention member form an angle in the range of approximately 20°-30°.

I claim:  
     
       1. A method of retaining a first generally cylindrical housing to a second generally cylindrical housing while allowing for relative rotation between the housings, the second generally cylindrical housing having a protrusion, the method comprising: 
       providing a sheet metal clip having an annulus disposed about a central axis, the annulus having a plurality of retention members, each of the plurality of retention member including a leg portion and a hook portion, the leg portion extending in a first direction from an inner perimeter of the annulus along the central axis, the hook portion projecting from the leg portion toward the central axis in a second direction opposite the first so as to define an imaginary perimeter concentric to the inner perimeter, the hook portion being acute to the central axis;  
       supporting the annulus of the clip within a retaining portion of the first housing; and  
       engaging the hook portion of the clip with the protrusion of the second housing in the first direction to position the protrusion into a space between the imaginary perimeter and inner perimeter so that the hook portion self-tightens on the protrusion when the second housing is moved away from the first housing along the central axis.  
     
     
       2. The method of  claim 1 , the step of providing further comprises: 
       providing the sheet metal clip with five retention members uniformly disposed about the inner perimeter of the annulus, each of the retention members having at least a portion of the free end of their respective hook portions located on an imaginary circle that is concentric to the inner perimeter of the annulus.  
     
     
       3. The method of  claim 1 , wherein each of the plurality of retention members includes an arcuate portion disposed between the hook portion and the leg portion. 
     
     
       4. The method of  claim 3 , wherein the plurality of retention members includes five retention members. 
     
     
       5. The method of  claim 4 , wherein the five retention members are disposed equi-angularly about the central axis. 
     
     
       6. The method of  claim 1 , wherein the providing further includes providing a plurality of stiffeners, at least one of the plurality of stiffeners being disposed on the inner perimeter between any two of the plurality of retention members so as to increase the structural rigidity of the clip. 
     
     
       7. The method of  claim 6 , wherein each of the plurality of stiffeners includes a lip facing in the first direction along the central axis. 
     
     
       8. The method of  claim 6 , wherein the sheet metal clip, including the plurality of retention members and stiffeners, includes an unitary sheet of metal. 
     
     
       9. The method of  claim 6 , wherein the providing further includes providing at least one cut-out on the inner perimeter of the annulus between each of the plurality of retention members and each stiffener. 
     
     
       10. The method of  claim 9 , wherein the at least one cut-out includes a semi-circle. 
     
     
       11. The method of  claim 1 , wherein the central axis and a plane passing through the hook portion of the at least one retention member form an angle in the range of approximately 20 degrees to approximately 30 degrees. 
     
     
       12. The method of  claim 11 , wherein the angle is of approximately 24 degrees. 
     
     
       13. The method of  claim 1 , wherein each of the plurality of retention members includes a substantially trapezoidal configuration. 
     
     
       14. The method of  claim 1 , further including: 
       Instron pull testing the first housing away from the second housing along the central axis; and  
       retaining the clip to the first and second housings until catastrophic failure of at least one of the second housing and the clip.